JP2013120053A - Heat pipe - Google Patents

Abstract

A heat pipe having further improved heat transport efficiency is provided.
A heat pipe uses a multi-hole tube. The heat pipe 100 uses a multi-hole tube in which a plurality of through holes are provided with a two-dimensional arrangement in the cross section of the multi-hole tube. The heat pipe 100 has at least one through hole 3d as a ventilation path through which cooling gas passes with both ends open, and the other through holes (3a, 3b, 3c) block both ends from the outside, One end communicates with another through hole, and the other end communicates with another through hole to form a flow path that reciprocates both ends of the multi-hole tube. A working fluid is sealed inside the flow path.
[Selection] Figure 1

Description

  The present invention relates to a heat pipe.

  A heat pipe is known in which a small amount of hydraulic fluid is sealed in an elongated cavity with both ends closed. The heat pipe is a device that transports heat using the heat of vaporization and the heat of condensation of the internal working fluid. One of the characteristics of the heat pipe is that it is inexpensive because it has a relatively simple structure in which a working fluid is sealed in a pipe made of metal (particularly, metal having high thermal conductivity such as aluminum or copper).

  The heat pipe has a simple structure, but various improvements have been proposed so far. For example, in Patent Document 1, a circulation flow generating means is provided in a plurality of heat insulating portions of a unit thin tube constituting a heat pipe so that a working fluid is circulated in a certain direction, thereby activating axial vibration. Heat pipes have been proposed. In Patent Document 2, in order to improve the heat transport capability, the cross-sectional area of the internal pores is set to a size that satisfies a specific condition, so that the heat transport by the sensible heat of the hydraulic fluid and the heat transport by the latent heat are performed. Heat pipes with a heat transport principle have been proposed.

JP-A-7-332881 JP 2005-337691 A

  The technology disclosed in the present specification provides a heat pipe with improved heat transport efficiency by a technology from a viewpoint different from the technologies of Patent Document 1 and Patent Document 2.

  The novel heat pipe disclosed herein utilizes a multi-hole tube. As is well known, a multi-hole tube is a long material provided with a plurality of through holes extending in the longitudinal direction of a single long material. In particular, the heat pipe disclosed in the present specification uses a multi-hole tube in which a plurality of through-holes are provided with a two-dimensional arrangement in the cross-section of the multi-hole tube (cross section orthogonal to the longitudinal direction). The heat pipe disclosed in the present specification has at least one through hole as a ventilation path through which cooling gas passes, and the other through hole blocks both ends from the outside and communicates with another through hole at one end. The other end communicates with another through-hole to form a flow path that reciprocates both ends of the multi-hole tube. A working fluid is sealed inside the flow path. The above heat pipe can be used as a self-excited vibration heat pipe.

  The heat pipe disclosed in the present specification does not use all of the plurality of through holes of the multi-hole tube as the flow path of the hydraulic fluid, but uses at least one through hole as a ventilation path. Since the through holes are two-dimensionally arranged in the cross section, the ventilation path is adjacent to at least two other through holes. Accordingly, the cooling gas passing through the ventilation path cools the hydraulic fluid in at least two adjacent through holes. Therefore, the heat transport efficiency of the heat pipe is improved. The cooling gas is preferably an inert gas cooled by a radiator or the like, but may be air.

  In addition, although it is preferable as a self-excited vibration type heat pipe that the ends of the flow path are connected to each other to form an annular flow path, the flow path has dead ends at both ends. There may be. If an annular flow path is configured to allow the working fluid to circulate, a reflux effect can be obtained and further improvement in heat transport capability can be expected.

  Since the above heat pipe uses a multi-hole tube with two-dimensionally arranged through holes and closes the end portion to form a flow path that reciprocates both ends of the multi-hole tube, it can be manufactured by a simple construction method. It also has the advantage of being able to. The multi-hole tube is preferably made of a metal having high heat transfer efficiency such as aluminum or copper.

  More preferably, the heat pipe communicates the through holes inside the end surface of the multi-hole tube by cutting out the wall separating the opening of the adjacent through hole at the end of the multi-hole tube, Three or more openings communicating with other through holes may be covered with a plate material. The structure of the end of the multi-hole tube can be simplified.

  Further, it is more preferable that a slit that communicates with the outside and through which the refrigerant gas passes is provided on the inner side surface of the ventilation path. It is possible to effectively use the ventilation path and efficiently cool the working fluid in the through hole (flow path) adjacent to the ventilation path. In order to use the slit effectively, it is better to install a cross flow fan in a through hole used as a ventilation path. Since the cross flow fan can increase the length of the outlet, it is suitable for passing air through the slit provided in the through hole.

  Furthermore, the heat pipe disclosed in the present specification may be formed with two flow paths having different flow path cross-sectional areas. Furthermore, a through-hole having a large cross-sectional area (a through-hole forming a flow path) is arranged in the center of the transverse cross section of the heat pipe, and a through-hole having a small cross-sectional area (a through-hole forming a flow path) around the periphery It is even better if is arranged. The hydraulic fluid is likely to vaporize in the channel having a small channel cross-sectional area. For this reason, a heat pipe having channels with different channel cross-sectional areas operates when a small amount of heat is received and a small channel with a small cross-sectional area on the outside operates. The road is activated. Therefore, the heat pipe described above operates quickly from when the amount of heat received is small, and can cope with a large amount of heat received.

It is a perspective view of the heat pipe of 1st Example. It is sectional drawing along the AA line of FIG. It is sectional drawing along the BB line of FIG. It is a perspective view of the multi-hole pipe used as the main body of the heat pipe of 1st Example. It is a perspective view of a main part (multi-hole pipe) with a communication path (front end portion). It is a perspective view of the main body which attached the communicating path (rear end part). It is a perspective view of the main body which attached the edge part cover (front-end part). It is a perspective view of the main body which attached the edge part cover (rear end part). It is a perspective view of the heat pipe of 2nd Example (state which removed the fan). It is a perspective view of the heat pipe of 2nd Example (state which attached the fan). It is a perspective view of the multi-hole pipe used as the main body of the heat pipe of 3rd Example. It is a perspective view of the main body which attached | subjected the communicating path. It is a perspective view of the main body which attached the edge part cover. It is a completion figure of the heat pipe of 3rd Example. It is a usage example of the heat pipe of 3rd Example. It is sectional drawing along the FF line | wire of FIG. 5E. It is sectional drawing along the GG line of FIG. 5E. It is a perspective view of the multi-hole pipe used as the main body of the heat pipe of 4th Example. It is a perspective view of the main body which attached | subjected the communicating path (front-end part). It is a perspective view of the main body which attached the communicating path (rear end part). It is a perspective view of the front end of the main body which attached the end cover and the communication short pipe. It is a perspective view of the rear end of the main body which attached the edge part cover. It is a completion figure of the heat pipe of 4th Example. It is a usage example of the heat pipe of 4th Example. It is sectional drawing along the HH line of FIG. 6G. It is sectional drawing along the II line of FIG. 6G.

  FIG. 1 shows a perspective view of the heat pipe 100 of the first embodiment. The heat pipe 100 is a device that cools the semiconductor chip 90, and a large number of semiconductor chips 90 are attached to the upper surface of the main body 2. As will be described in detail later, four through holes 3 a, 3 b, 3 c, and 3 d are formed inside the main body 2. In addition, in FIG. 1, only the opening part is shown with the broken line about the through-holes 3a, 3b, and 3c hidden by the edge part cover 6a and the sealing plug 7. FIG. The four through holes are arranged two-dimensionally in two rows and two rows in the cross section of the main body 2. Three of them (through holes 3a, 3b, and 3c) are sealed by a plate-like end cover 6a (and an opposite end cover 6b) and a sealing plug 7. The three sealed through holes are interconnected inside to form a single flow path. A small amount of hydraulic fluid is sealed in the flow path. The hydraulic fluid is, for example, water or ammonia. In addition to the working fluid, the wick may be enclosed in the flow path. The remaining one (through hole 3d) that is not sealed is used as a ventilation path with both ends open. A fan 9 is attached to one end of the ventilation path (through hole 3d). An arrow R1 in FIG. 1 indicates the flow of wind by the fan 9.

  A cross section taken along line AA in FIG. 1 is shown in FIG. 2A, and a cross section taken along line BB is shown in FIG. 2B. The hydraulic fluid is not shown. Hereinafter, for the sake of explanation, the front end portion of the main body 2 in the Z-axis direction is referred to as a front end, and the rear end portion in the Z-axis direction is referred to as a rear end. The definitions of the front end and the rear end are the same in other embodiments. The through holes 3a and 3b are connected at the front end 2A of the main body 2 through the communication path 4a (FIG. 2A). Moreover, the through holes 3b and 3c are connected through the communication path 4b at the rear end 2B of the main body 2 (FIG. 2B). Eventually, the through holes 3a, 3b, and 3c form a flow path 8 that reciprocates between the front end and the rear end of the main body 2 by 1.5.

  Next, the manufacturing process of the heat pipe 100 will be described with reference to FIGS. 3A to 3E. FIG. 3A is a perspective view of the main body 2. The main body 2 is a long material having a rectangular cross-sectional outer shape, and has four through holes 3a-3d penetrating the long material in the longitudinal direction. A long material having a plurality of through holes extending in the longitudinal direction of the long material is called a multi-hole tube. The main body 2 is also a multi-hole tube. As shown well in FIG. 3A, the through holes 3 a to 3 d are two-dimensionally arranged in two rows in the vertical and horizontal directions in the cross section of the main body 2. In other words, “two-dimensionally arranged” means that a plurality of through holes are arranged so that a plurality of through-holes are arranged in either of two directions orthogonal to each other in the cross section of the main body 2. That is. The transverse section corresponds to a section orthogonal to the longitudinal direction of the main body 2 (Z direction in the coordinate system in the drawing).

  The main body 2 is made by extrusion molding of aluminum which is one of plastic working methods. The material is not limited to aluminum but may be copper. Moreover, although the heat pipe 100 of a present Example has a total of four through-holes of 2 rows each in length and width, it should be noted that the number of through-holes may be any number.

  Next, communication passages 4 a and 4 b are formed at the end of the main body 2. 3B is a perspective view of the front end 2A of the main body 2 with the communication path 4a, and FIG. 3C is a perspective view of the rear end 2B of the main body 2 with the communication path 4b. The communication path 4a is formed by cutting out a wall that separates the openings of the through holes 3a and 3b at the front end 2A. The communication path 4b is formed by cutting out a wall that separates the openings of the through holes 3b and 3c at the rear end 2B. Therefore, when the end cover 6a, 6b (described later) is attached, the through holes 3a, 3b, 3c are blocked from the outside and communicate with each other inside the end surface of the main body 2 (multi-hole tube). As described with reference to FIGS. 2A and 2B, the through holes 3 a, 3 b, and 3 c are connected to one flow path 8 that reciprocates both ends of the main body 2 by 1.5 through the communication paths 4 a and 4 b. Become.

  End covers 6a and 6b for closing the opening of the through hole and an injection short tube 7 for injecting the working fluid are attached to the front end 2A and the rear end 2B of the main body 2 thus manufactured. FIG. 3D is a perspective view of the front end 2A. A plate-like end cover 6a that closes the openings of the through holes 3a and 3b is attached to the front end 2A, and an injection short cylinder 7 is attached to the opening of the through hole 3c. FIG. 3E is a perspective view of the rear end 2B. A plate-like end cover 6b that closes the through holes 3a, 3b, and 3c is attached to the rear end 2B. Next, after a small amount of hydraulic fluid is injected through the injection short cylinder 7, the injection short cylinder 7 is closed to close the through hole 3c (see FIG. 1). The injection short cylinder 7 is also made of aluminum and can be easily closed by a method such as welding or caulking. Finally, the fan 9 is attached to complete the heat pipe 100 shown in FIG.

  The advantages of the heat pipe 100 will be described. The heat pipe 100 uses a multi-hole tube in which a plurality of through holes are two-dimensionally arranged. Multi-hole tubes are inexpensive to make by extrusion. Here, in the case of manufacturing a multi-hole having the same shape and the same number of through-holes in a row and in the case of manufacturing a multi-hole tube in which the through-holes are two-dimensionally arranged, the former is the vertical and horizontal directions of the extrusion port of the mold. The ratio increases, and the latter requires a lower aspect ratio. Therefore, the multi-hole tube having the two-dimensionally arranged through holes can be manufactured at a lower cost than the multi-hole tube having the one-row arranged through holes.

  The heat pipe 100 uses one of a large number of through-holes as a ventilation path and seals the other through-hole as a flow path for the working fluid. A plurality of through holes constituting the flow path of the hydraulic fluid are provided with a two-dimensional arrangement. Therefore, the ventilation path is adjacent to at least two of the through holes constituting the flow path. Since the air (cooling gas) passing through the ventilation path efficiently cools the working fluid passing through the adjacent through holes, the heat transport efficiency of the heat pipe is improved.

  The heat pipe 100 can also be used as a self-excited vibration heat pipe. The self-excited vibration type heat pipe uses its own vibration force as a force for moving the working fluid (heat medium) in the pipe. In that case, the flow channel portion (the flow channel portion corresponding to the through hole 3a) located in the immediate vicinity of the semiconductor chip 90 corresponds to the evaporation portion of the self-excited vibration timing heat pipe. The flow path portion corresponding to the through holes 3b and 3c corresponds to the condensing portion. The flow path is in a state where gas phase portions and liquid phase portions exist alternately. In the evaporation section, the working fluid takes away heat from the semiconductor chip 90 and evaporates to generate new bubbles (the heat medium takes away heat of vaporization). In the evaporation section, the pressure increases due to the generation of bubbles. On the other hand, in the condensing part, the bubbles are liquefied by the cooling action (at this time, the heat medium releases the heat of condensation), and the pressure decreases. A self-excited pressure oscillation occurs due to the pressure difference between the evaporation section and the condensation section, and the heat medium in the gas phase and the liquid phase in the flow path moves from the evaporation section having a high pressure to the condensation section having a low pressure. This movement of the heat medium causes both latent heat and sensible heat to be transported simultaneously.

  Next, the heat pipe 100a of the second embodiment will be described with reference to FIGS. 4A and 4B. The difference from the heat pipe 100 of the first embodiment is that the side face of the main body 2 is provided with slits 2f and 2g leading to the ventilation path (through hole 3d) and the cross flow fan 19 is adopted. 4A shows a state where the cross flow fan 19 is removed, and FIG. 4B shows a state where the cross flow fan 19 is attached. As shown in FIG. 4A, the slits 2f, 2g extend long from almost the end of the main body 2 along the through hole 3d. The slits 2 f and 2 g are provided at an angle of approximately 90 degrees with each other when viewed from the longitudinal direction (Z direction) of the main body 2. As shown in FIGS. 4A and 4B, the cross flow fan 19 is attached to the inside of the through hole 3d used as a ventilation path. As shown in FIG. 4B, the cross flow fan 19 causes the wind to enter the ventilation path from one slit 2f, and the wind flows out from the other slit 2g (arrows R2 and R3 indicate the flow of the wind). By using the slits 2g and 2f and the cross flow fan 19 that can increase the length of the ejection port, the ventilation path can be used effectively.

  Next, the heat pipe 100b of the third embodiment will be described with reference to FIGS. 5A to 5G. The heat pipe 100b of the third embodiment has two flow paths having different cross-sectional areas. In addition, one flow path is an annular closed path through which both ends of the flow path are connected and the enclosed hydraulic fluid can circulate.

  FIG. 5A is a perspective view of a multi-hole tube that becomes the main body 22 of the heat pipe 100b. This multi-hole tube has two types of through holes. One is a first through hole 3a-3d arranged in the center of the main body 22 in the cross section, and the other one is a first through hole arranged around the first through hole in the cross section. 2 through holes. The cross-sectional area of the second through hole is smaller than the cross-sectional area of the first through hole. In FIG. 5A, all the second through holes are not labeled, but the second through holes are collectively referred to as “second through holes 13”. Further, the four first through holes 3a to 3d are collectively referred to as “first through holes 3”. As in the first embodiment, for convenience, the end on the Z direction front side of the main body 22 is referred to as a front end 22A, and the end on the Z direction rear side is referred to as a rear end 22B.

  FIG. 5B is a perspective view of the main body 22 with a communication path. The communication path is formed by cutting out a wall that separates adjacent through-hole openings at the end of the main body 22. The communication path of the first through hole 3 is the same as that of the first embodiment. The communication path of the second through hole 13 is the same as that of the first through hole. The communication path 14a is formed by cutting out a wall that separates the openings of the second through hole 13b and the second through hole 13c. Similarly, the communication path 14b is formed by cutting out a wall separating the opening of the second through hole 13d and the second through hole 13e. In this way, a communication path is formed by cutting out the walls separating the openings by taking two adjacent openings as a set. It should be noted that the through holes 13a and 13f do not form a communication path. About the through-holes 13a and 13f, both are connected by another member later. Similarly, a communication path is formed at the rear end 22B of the main body 22. However, at the rear end 22B, a communication path is formed with respect to two through holes in which no communication path is formed at the front end 22A. For example, since the second through holes 13c and 13d do not have a communication path formed at the front end 22A, a communication path is formed between the second through holes 13c and 13d at the rear end 22B. Thus, the second through holes 13c and 13d do not communicate with each other at the front end 22A but communicate with each other at the rear end 22B. Thus, when both ends of the main body 22 are closed by the end covers, all the second through holes 13 constitute one flow path.

  FIG. 5C shows a state in which the end cover 6 a, the injection short tube 7, and the communication short tube 17 are attached to the front end 22 </ b> A of the main body 22. The injection short cylinder 7 is attached to the first through hole 3c. The communication short cylinder 17 is attached so as to surround the second through holes 13a and 13f. The end cover 6a covers the openings of the first and second through holes other than the first through holes 3c and 3d and the second through holes 13a and 13f at the front end 22A. Although not shown, an end cover 6b that covers a through hole (including the second through hole 13) other than the first through hole 3d is attached to the rear end 22B of the main body 22. The first through hole 3d is used as a ventilation path.

  FIG. 5D is a completed view of the heat pipe 100 b in which the injection short tube 7 and the communication short tube 17 are closed and the fan 29 is attached. The injection short cylinder 7 is closed after injecting a small amount of hydraulic fluid into the first through-hole 3c and becomes a sealing plug. The injection short tube 7 is made of aluminum and can be easily closed by welding or caulking. The first through holes 3a to 3d form a flow path that reciprocates the main body 22 by 1.5, as in the first embodiment.

  The communication short cylinder 17 is closed after injecting a small amount of hydraulic fluid into the second through hole 13a. The communication short cylinder 17 is also made of aluminum, and can be easily closed by processing such as welding or caulking. However, the communication short cylinder 17 is closed leaving a space for communicating the second through holes 13a and 13f inside. Thus, the plurality of second through-holes 13 reciprocate a plurality of times between both ends of the main body 22 to form a flow path that makes a circle in its entirety. The flow path by the 2nd through-hole 13 is mentioned later. A fan 29 is attached to the opening of the first through hole 3d at the rear end 22B of the main body 22.

  FIG. 5E is a usage example of the heat pipe 100b. A plurality of semiconductor chips 90 are attached to the upper surface of the main body 22. When the fan 29 (not shown in FIG. 5E) is driven, wind passes through the first through hole 3d. Arrow R4 indicates the flow of wind. The air passing through the ventilation path (first through hole 3d) cools the hydraulic fluid passing through the plurality of through holes (including the second through hole) around the first through hole 3d.

  A cross section taken along line FF in FIG. 5E is shown in FIG. 5F, and a cross section taken along line GG is shown in FIG. 5G. Note that the fan 29 is not shown. As shown in FIG. 5F, the second through holes 13 a and 13 b communicate with each other on the rear end 22 </ b> B side of the main body 22. The second through holes 13b and 13c communicate with each other on the front end 22A side of the main body 22 (communication path 14a). The second through holes 13 c and 13 d communicate with each other on the rear end 22 </ b> B side of the main body 22. The second through holes 13d and 13e communicate with each other on the front end 22A side of the main body 22 (communication path 14b). In this way, the second through holes 13a, 13b, 13c, 13d, and 13e constitute one flow path 8 that reciprocates between both ends of the main body 22 a plurality of times. Other second through holes not shown in FIGS. 5F and 5G are also communicated with each other. Further, as shown in FIG. 5G, the opening on the front end side of the second through hole 13a and the opening on the front end side of the second through hole 13f are communicated with each other through a communication short cylinder 17. The opening on the front end side of the second through hole 13 a and the opening on the front end side of the second through hole 13 f correspond to both ends of the flow path 8. Eventually, all the second through holes 13 reciprocate a plurality of times between both ends of the main body 22 to form a single flow path through which the internal working fluid can circulate. The flow path formed by the first through hole 3 has the same structure as the flow path 8 of the heat pipe 100 of the first embodiment.

  The advantages of the heat pipe 100b will be described. The heat pipe 100b has two flow paths having different cross-sectional areas. The flow path having a large cross-sectional area (the first flow path configured by the first through holes 3) is located in the center of the cross section of the main body 22. A channel having a small cross-sectional area (second channel constituted by the second through-holes 13) is arranged around the first channel in a cross section. The smaller the cross-sectional area, the easier it is for the hydraulic fluid to vaporize / condense. Therefore, the heat pipe 100b transports heat by the working fluid in the second flow path as long as the amount of heat received is small. Moreover, since the second flow path is disposed closer to the surface of the heat pipe 100b than the first flow path, heat is easily exchanged with the outside. On the other hand, the first flow path having a large cross-sectional area can transport a large amount of heat. The heat pipe 100b having two flow paths having different flow path cross-sectional areas can be operated from a small amount of received heat and can be transported to a large amount of heat.

  Next, a heat pipe 100c according to a fourth embodiment will be described with reference to FIGS. 6A to 6I. FIG. 6A is a perspective view of a multi-hole tube that becomes the main body 32 of the heat pipe 100c. This multi-hole tube has nine through holes 3a-3i having the same cross-sectional size. The nine through holes are two-dimensionally arranged in the cross section of the multi-hole tube (main body 32). This multi-hole tube is also made by extrusion. The heat pipe 100c has three ventilation paths 3g, 3h, and 3i.

  Next, a communication path is formed at the end of the main body 32. 6B is a perspective view of the front end 32A of the main body 32 with the communication paths 4a and 4b, and FIG. 6C is a perspective view of the rear end 32B of the main body 32 with the communication paths 4c, 4d, and 4e. The communication path 4a is formed by cutting out a wall that separates the openings of the through holes 3b and 3c at the front end 32A. The communication path 4b is formed by cutting out a wall that separates the openings of the through holes 3e and 3d at the front end 32A. The communication path 4c is formed by notching a wall separating the openings of the through holes 3f and 3e at the rear end 32B. The communication passage 4d is formed by cutting out a wall that separates the openings of the through holes 3a and 3b at the rear end 32B. The communication path 4e is formed by cutting out a wall that separates the openings of the through holes 3c and 3d at the rear end 32B. The six through holes 3 a, 3 b, 3 c, 3 d, 3 e, and 3 f serve as a flow path that is connected to one that reciprocates the both ends of the main body 32 three times by the communication path 4 a-4 e. The openings of the through holes 3a and 3f at the front end 32A are communicated later by a communication short cylinder 37. As a result, the flow path becomes an annular closed flow path through which the working fluid can circulate. In the heat pipe 100c, the through holes 3g, 3h, 3i are used as ventilation paths without being closed at both ends.

  At the front end 32A of the main body 32 made in this way, an end cover 6a that closes the opening of the through hole and a communication short cylinder 37 that injects hydraulic fluid and communicates the through holes 3a and 3f are attached. FIG. 6D is a perspective view of the front end 32A. At the front end 22A, a plate-like end cover 6a that closes the openings of the through holes 3b, 3c, 3d, and 3e is attached, and a communication short cylinder 37 is provided so as to surround the openings of the through holes 3a and 3f. It is attached. FIG. 6E is a perspective view of the rear end 32B. At the rear end 32B, a plate-like end cover 6b that closes the openings of the through holes 3a, 3b, 3c, 3d, 3e, and 3f is attached. Next, after a small amount of hydraulic fluid is injected through the communication short cylinder 37, the communication short cylinder 37 is closed to close the openings of the through holes 3a and 3f (see FIG. 6F). At this time, the communication short cylinder 37 is closed while leaving a space communicating the through holes 3a and 3f. Thus, the six through holes 3a, 3b, 3c, 3d, 3e, and 3f reciprocate a plurality of times between the both ends of the main body 32, and constitute a flow path that is circular in its entirety. Finally, three fans 39 that send air to the openings of the through holes 3g, 3h, and 3i are attached to the rear end 32B of the main body 32, and the heat pipe 100c is completed.

  FIG. 6G is a usage example of the heat pipe 100c. A plurality of semiconductor chips 90 are attached to the upper surface of the main body 32. When the fan 39 is driven, the wind passes through the three through holes 3g, 3h, and 3i. Arrow R5 indicates the flow of the wind.

  A cross section taken along line HH in FIG. 6G is shown in FIG. 6H, and a cross section taken along line II is shown in FIG. 6I. In FIG. 6II, the fan 39 is not shown. As shown in FIG. 6H, the through holes 3a and 3b communicate with each other on the rear end 32B side of the main body 32 (communication path 4d). The through holes 3b and 3c communicate with each other on the side of the front end 32A of the main body 32 (communication path 4a). Similarly, the six through holes 3a, 3b, 3c, 3d, 3e, and 3f are connected to each other in this order, and one flow path that reciprocates a plurality of times between both ends of the main body 32. 8 is formed. As shown in FIG. 6I, the through holes 3a and 3f communicate with each other on the side of the front end 32A of the main body 32 by a communication short cylinder 37 whose front end is closed. That is, the six through holes 3 a, 3 b, 3 c, 3 d, 3 e, and 3 f constitute an annular flow path 8. Since the through-hole 3g is used as a ventilation path, both ends remain open.

  The heat pipe 100c uses an even number of through holes for the flow path of the self-excited vibration heat pipe. Therefore, the refrigerant introduction pipes can be connected on the same plane. Thereby, both ends of the flow path can be adjacent to each other, and it is easy to connect to form an annular flow path. In the self-excited vibration heat pipe, by connecting both ends of the flow path to form an annular flow path, a reflux effect can be obtained and the heat transport capability can be improved by about 10%.

  Points to be noted regarding the heat pipe of the embodiment will be described. In the embodiment, the length of the main body is drawn relatively short for convenience of drawing, but the length of the main body can be increased according to the object to be cooled. In the embodiment, the semiconductor chip 90 to be cooled is disposed only on the upper surface of the heat pipe, but the surface on which the cooling object is disposed may be the side surface or the bottom surface of the heat pipe. The number of through holes is not limited as long as they are two-dimensionally arranged in the cross section of the main body.

  The end cover of the plate material such as the end cover 6b of the first embodiment and the end cover 6a of the third embodiment may cover three or more openings. Since three or more openings can be covered with a single plate material, the manufacture of the heat pipe is simplified. In the heat pipe 100c of the fourth embodiment, instead of the communication short cylinder 37, a wall separating the opening of the through hole may be cut out and covered with a plate material.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2, 22, 32: Main body (multi-hole tube)
2f, 2g: slit 3: through-holes 4a, 14a, 14b: communication passages 6a, 6b: end cover 7: injection short tube (sealing plug)
8: flow path 9, 29, 39: fan 13: through hole 14a communication path 14b communication path 17: communication short cylinder 19: cross flow fan 90: semiconductor chips 100, 100a, 100b, 100c: heat pipe

Claims (7)

  A multi-hole tube, in which a plurality of through-holes are provided with a two-dimensional arrangement in a cross section perpendicular to the longitudinal direction, at least one through-hole is a ventilation path through which cooling gas passes, The through-holes of both ends are blocked from the outside, communicated with other through-holes at one end and further communicated with another through-hole at the other end, and have a flow path reciprocating between both ends of the multi-hole tube. A heat pipe formed and sealed with a working fluid inside a flow path.   The wall separating the openings of the adjacent through holes at the end of the multi-hole tube is cut out so that the through holes communicate with each other inside the end face of the multi-hole tube, and three or more openings are covered with a plate material. The heat pipe according to claim 1, wherein the heat pipe is a heat pipe.   The heat pipe according to claim 1 or 2, wherein the flow path is an annular flow path whose ends are connected to each other.   The heat pipe according to any one of claims 1 to 3, wherein a slit that communicates with the outside and through which the refrigerant gas passes is provided on an inner surface of the ventilation path.   The heat pipe according to claim 4, wherein a cross flow fan is attached to the inside of the ventilation path.   The heat pipe according to any one of claims 1 to 5, wherein two flow paths having different flow path cross-sectional areas are formed.   The heat pipe according to claim 6, wherein a through-hole having a large cross-sectional area is disposed at a central portion in a cross section of the heat pipe, and a flow path having a small cross-sectional area is disposed around the through-hole.

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